The present invention relates to utilization of an electronic disk subsystem and, more particularly, to a means for checking coincidence between data in two dual type electronic disk units.
In order to conventionally read out and collate dual data, these data are read out from two electronic disk units by different read sequences by software or a controller, and the readout data are compared with each other.
In such a conventional system, since the dual data are checked such that read commands are supplied to the two electronic disk units by different sequences by software or a controller, and the readout data are compared with each other, the software or controller is overloaded as compared with an operation for reading out single written data, thereby undesirably degrading system performance.